


Experiment

by Sans Culottes (sansculottes)



Category: Undertale (Video Game)
Genre: Domestic Fluff, First Kiss, Fluff, Graphic Description, I suck at tagging shit, No Sex, One-Shot, Other, Post-Canon, Reader Is Not Frisk, i guess?, kiss
Language: English
Status: Completed
Published: 2015-12-10
Updated: 2015-12-10
Packaged: 2018-05-06 00:51:48
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,097
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5396627
Author URL: https://archiveofourown.org/users/sansculottes/pseuds/Sans%20Culottes
Summary: <blockquote class="userstuff">
              <p>You finally find out what has been bothering your beloved one for the last couple of weeks. Spoiler alert: it's a good time (he even set the ketchup aside for this).</p>
            </blockquote>





	Experiment

**Author's Note:**

> This is the first time I decide sharing something I wrote. Hoo boy, I'm anxious! 
> 
> Although mature for graphic descriptions, this isn't smut, I headcanon ace Sans. Because, you know... (coughs) Please don't hate me (coughs) Even 'cause that doesn't mean he can't have fun in some other ways. 
> 
> If you're uncomfortable with graphic descriptions of a kiss, I'm sorry, this isn't the thing for you, buddy. :C

It never really bothered you that his usual display of affection was nuzzling against different parts of your body. The gentle hand to nose nuzzle, the chaste nose to nose nuzzle and the wrecking nose to neck nuzzle were definitely your top 3, by far above any kiss or hickey you had experienced so far. Unlike you previous partners, there was something very special about your monster boyfriend. Perhaps the fact you shared the a common condition made your bond so strong, you couldn't really tell. All you knew is it was so, so, very special, and you wished he felt the same. 

However, watching romcom with the short skeleton would usually lead you to detect a slight uneasiness coming from him. You didn't pay much attention to it, though. Had you questioned it, you know he'd have danced around the subject. Besides, witnessing the blue tint spreading over his features was always a welcomed, rare sight. So you'd just let it come and go on its own, the punishment for letting your boyfriend silently worry over his own issues being the fact you'd have to cope with not knowing what was going on his skull until he was willing to share it. Who knows, maybe you'd get a reward for being patient? 

And so it went, until, apparently, he couldn't hold it anymore. Surprisingly, he didn't get anxious watching a romcom, nope, this time you were watching a not very recent hero movie from 2002. 

"Hey, kid," he paused the movie as the main character interacted with his love interest in a dark, damp alley. "I, uh, gonna grab me something to munch on. Want something?"

"I'm cool. Dontcha wanna leave the movie rolling? You can see the TV from the kitchen anyways" You knew exactly what was gonna happen at that moment of the movie, thus you suggested it so he'd at least not have to watch it by your side and feel awkward about it this time. See? You're such a good lover. 

"Hmm" he pondered for a while, then handed you the remote and moved towards the kitchen "okay, sure" shortly after, he hummed cutely as you heard clattering from the fridge. 

"At the door, bae" considering you knew what he was looking for, you announced its position. 

"Oh, thanks. Why'd you move it?" He came back with a bag of chips and a ketchup bottle in hands. 

"Figured it'd be easier for you to find. Isn't it? If it doesn't work, we can keep it at the usual spot."

"Nah, it's cool like that. It's really easier to ...find" he finishes his sentence gulping dry void, and you both notice he had come back to the living precisely when the couple has its famous kiss scene. Hadn't he looked so ridiculously adorable blushing, you feel like you would have felt bad for him. His eyes darts from the screen to you and, noticing yours locked on him, his pupils fled back to the screen just as fast. It takes a while, but words come from him. "Uh, can I ask ya something?"

"Hit me" anticipation frolicking within your guts, you brace yourself for the possibility of understanding his mind a bit more from now on.

"...Do you miss kissing?" An anxious, shy grin took hold of his expression.

You figured after dating Sans for a while that a skeleton's face didn't work the same as a human's. As much as it could move around, it had its limitations, so you never really demanded anything from him. Also, skeletons obviously lacked some body parts. But if that bothered you, you wouldn't be with him, right? Besides, to your eyes, he's perfect just the way he is. 

"Oh, Sans, honey" eyebrows bending in a pitiful glare, you smile at his silly concern. So behind the cocky, laid back, punny skeleton was a cuddly marshmallow with insecurities as anyone else's. You loved it. "Not at all. So that's what's been eating ya?"

"Oh, wow. You noticed?" A little sweat bead sprouted by his temple. 

"Yeah. I couldn't really tell what was bothering you, though. And I didn't want to poke a wound, so I just let you do your thinking."

"That's a tad... Sweet, I guess." A sweet, sweet grin lights up his cheekbones. Although you did have your fun watching him get flustered out of nowhere, you also knew Sans was the kind of guy who hated being under someone else's spotlight, especially if it meant they're concerned about him. 

"Why you asking?" 

"I just... Noticed that's like everywhere. Movies, comic books, soap operas, anime. So I've been cracking my skull to come up with a solution for that" as he snorted, his shiny pupils finally look into yours "if ya ever needed it, that is. But if we're good then forgeddaboudit."

"Oh." Such adorableness nearly stole your ability to speak completely. But you couldn't just let him get away with that. "Don't let things like that eat your thoughts, hun. We can always try new stuff. Just talk to me! That's what I'm here for, right?"

"I didn't have enough data before. But now, I think I'm cool. Wanna try it out?" Pretending to recover by putting up a snarky smug on his face, his half lidded eyes invite you. 

 _Enough data_ , he said? His weird, scientific side was showing. You digged it. 

"Then, uh, I'm game, I guess. Show me what's that data you got, handsome." Extending a hand, you invite him to sit on the couch. Responding quickly, his fingers entwine with yours and he joins the seat by your right, dropping the chips and ketchup at the side table.

You had a part to play from here on, given this situation. As shy as you were, you had to be strong for him now. I mean, he did brood over a subject that was linked to your satisfaction for quite a while, so responding positively is the less you can do. You caressed his shoulder, encouraging him, filled with determination. 

"Just, tell me if I freak you out, 'kay?" His hands carefully framed your face as they did when he nuzzled against you, and it already got your heart fluttering madly.

The bridges of your noses meet, you close your eyes. You feel warmth take your cheeks and a dim blue light piercing through your closed lids. Little points of pressure pinch on your lower lip, making you gasp and your eyes pop open. 

"S-Sorry. Did that hurt?" He instantly breaks contact, a hand by your chin manifested his concern. 

"N-no. I was just startled. I... wasn't expecting this at all." The way his brows were slightly pointing downwards reinforced how mixed were your current signals, so you try stepping up your game. "Your teeth... I mean... It... Felt **good**." It felt as if though fireballs were casted onto your cheeks as you realize how exciting this whole situation was. "I'm okay with it. I just... Can I see them?"

With these words, his face melts in a relieved smile. He sigh laughs, gaping his jaw. Your fingers ran through his pointy fangs. He probably bit you with his head tilted to the side, making his canines more evident. No wonder it was a bit alien. Awed by your recent discovery, your thumb slides over its shape, recording it into your brain as you study it. "Wow. How come I never noticed these?" Once done, you return your hands to his collarbone, where they were before. 

"My smile is probably so bright it blinds ya, that's why" the hand by your waist plays with the rim of your sweater. "There's still something else I wanna try. It's a bit more... invasive. If that's okay with you, I mean." His glance requested permission to proceed. 

"Sure, go ahead" you close your eyes again, dropping a peck on his cheekbone. His face travels to stand once more aligned to yours. What else could he show you? Could it possibly be as thrilling, perhaps even more, than being bit by him?

His teeth brushed against the sides of your lips, as if preparing you to their touch again. Upon reaching their original destination, he seemed to study your reaction to it. Nibbling your cupids bow, then the lower lip, pulling them, testing their elasticity. You respond by tilting your head a little, requesting those pointy fangs again, pulling his face closer, arms tangled around his neck. 

He shifted his weight to his knees, devoting his posture completely to this. Right hand by your cheek and left reaching for your back, he pulled you even closer, if possible. Hadn't your lips been busy, you'd ask him to bite you harder. Discovering these feelings could be unlocked by such a chill guy wouldn't stop surprising you, it seems.

It wasn't until the faint blue hue reappeared through your closed eyelids that you noticed it was gone before. As you started questioning what could that mean, you feel yet another texture by your lips. It was soft, smooth, warm, and the slightest brush against your skin sent spikes of dullness across your face. A low vowel escaped through the back of your throat, you instinctively parted your lips, gripping his shirt. He accepted the invitation almost immediately, heading through them.

You couldn't care less how he managed that, but he was french kissing you and it felt awesome. Lifting your tongue shyly against him, you take in more of the little electric sparks that were sent through his appendage. Realization strikes you: it was, literally, a magic touch, bursting with energy coming from his very soul. Thirsty for comprehension, your tongue circle his, tracing its shape, noticing its pointy end, how your saliva flowed around it and trying not to focus on the extraordinary sensation delivered, for the sake of your sanity.

Battling your way to his territory, you press against the cool surface of his pointy teeth and boney lips, tracing the surroundings, obliging to the little grab on your lower scalp that asked for more. Hands guiding him, you tilt his head a little to the right, clashing surfaces reducing the distance between them some more as they'd adapt to the foreigner. The slight swoon you felt from his shoulders along with a moan revealed he probably felt as good as you did.

Neither of you were really sure how long you spent lost on each other, but you could definitely tell by your ragged breath that you needed a break. He tugs on your hair and nibbled your lips lazily one last time before backing away, breaking the damp, thin line that insisted on connecting your lips with his thumb. You stare at him, eyes squinting, yet expression dumbfounded. 

"You're not gonna tell me you never did that, are ya?" Your fingers rushed to brush against your lips. They were still tingly under the lingering magic energy. 

"I was too... Lazy to try it with anyone, really."

"Bullshit. You're no kid, dude. How the hell would you come up with that?" You punch his arm lightly. 

"I'm serious." A subtle melancholy reaches his eyes, you figure he's talking about the resets he feared so much. If you didn't like the concept of that, no wonder he'd be traumatized after experiencing it. Gotta make up for letting him recall the subject. "I guess you can say all those cheesy scenes I watched with you filled me with determination...?" Awkwardly chuckling, he scratched the back of his neck. 

"Wow. I guess you're not only a genius for science stuff, then" sigh laughing, you rest your head on his shoulder, eyes still locked on his. "Good job, bonehead"

"I'd rather compare that to art, really. Science already exists... Now, art... It requires a muse, ya know?" his silly wink never sent such a powerful chill up your spine. Guess you're still under the influence of his magic. You couldn't really focus on any other feeling properly yet, but you were sure as heck blushing like a tomato. Smooth little bastard. 

"Well, you better keep finding ways to a _muse_  me, then" you wink back, trying to level up to his level of coolness despite the rushed heartbeats he never failed to steal from you. 

"Ayyy," he wraps his arm around you tightly, cheeky, proud smile bursting up after your silly joke "now that's the human that I fell for! C'mere, buddy." 

You chuckle and cuddle comfortably together as you picked another movie to watch, since the one you were watching somehow already had the credits rolling...

**Author's Note:**

> Tuesday. Half past midnight. I had this vague concept in my mind of what it would be like to kiss him. I grab my phone and start sketching the concepts on a memo. "I'll write it tomorrow evening", I said. "I need to wake up at 6:30."
> 
> 1 hour later. Words burst into "plot". "Nggghhhh, but I should be sleeping". I dared to remind myself. But it refused.
> 
> Half past two in the morning: fan fiction is done. I drop the phone and take like 15 minutes to proofread and lull myself to sleep. (So if y'all find any typos, lemme know, 'kay?)
> 
> Wednesday. Eight in the morning. I grab a seat at the public transportation, lower the phone's screen luminosity to its minimum and start reading what I came up with. Had to stop twice due to uncanny snorting and blushing at what seemed like a black screen to the eyes of others. "What have I done?", I questioned my muses, "why do you not work like that when I'm fully awake?"
> 
> A lady takes the seat by my side. Fix some typos, add a couple of sentences. Stopped reading it, embarrassed as heck.
> 
> "Writing soft monster kink while riding a bus", I thought. "What am I doing with my life"
> 
> Nine in the morning. I'm sitting at work, writing the tags and notes to remember this shameful, sinful moment of my life forever (and give the readers a good laugh at my pathetic situation). I save it to review one last time before posting it later the week.
> 
> R u having a giggle there m8? You better be.
> 
>  
> 
> Anyways, thank you for taking a time to read this. I hope you enjoyed it. :>


End file.
